For info:
YAMS Wayfinder documentation
I see. You want to use the "link attributes" field in a Wayfinder template. This is normally done via the [tt][+wf.attributes+][/tt] placeholder. I can’t see any reason why this wont work like normal. The link attributes field is not multilingual and should be parsed like normal by the Wayfinder snippet.
A standard YAMS-ified Wayfinder snippet call looks like:
[tt][[Wayfinder?
other args... &rowTpl=`@FILE:assets/modules/yams/tpl/wayfinder/docr/row.tpl`]][/tt]
where the contents of the row.tpl file are
<li[+wf.id+][+wf.classes+]>
<a href="(yams_docr:[+wf.docid+])" title="[[YAMS? &get=`data` &docid=`[+wf.docid+]` &from=`pagetitle`]]" [+wf.attributes+]>[[YAMS? &get=`data` &docid=`[+wf.docid+]` &from=`menutitle`]]</a>
[+wf.wrapper+]
</li>
So the default YAMS templates already include the [tt][+wf.attributes+][/tt] placeholder. Are you using the default YAMS Wayfinder templates or your own customised ones?